Yeh, I pretty regularly find umbraphage (i.e. the best light qua actually lighting things up in the game) or the lightbringer wand (a faintly disgustingly powerful summoning artifact that can largely carry you through the tail end of the west and a chunk of the east) before I hit voratun crap. Burning star, too, though that's more quality of life upgrade than power up. There's some stuff, basically. Occasionally find d-steel or stralite stuff that sticks around past the tier 5, too. Admittedly it's usually a 30% global slow or somethin' non-weapon randart or rare, but it's there.
So far as the early game stuff goes, skipping is totally fine. The only thing of the tier one dungeons I'd recommend as required would be trollmire, kor'pul, and the crystal caves (and I want to say heart if you're a dwarf?), to get their backup guardians to spawn later on.
Still, if it's still too much (and I totes wouldn't blame you if it is), you might check out addons. Know there's some kind of quick tome thing, and I think there's a handful of others aimed at squelching some of that early game tour. Pretty regularly play the campaign uncapper, ferex, which accelerates XP gain enough you can comfortably skip about half the t1s (and probably a t2 or two) if you don't want to bother with them.
Also find ember's campaign to be a fair bit less painful on that front. Helps that there's only 2-4 tier one dungeons (depending on what you consider dead cow land and the outpost) there, heh.
... and yeah, adventurer is fine. If you want the permadeath feel, you can always just tell the respawn critter to off you. It doesn't take something away, just gives you a bit more choice in whether you want to keep playing or not.